NASA's 'Armageddon'-style Asteroid Deflection Mission Takes Off Next Month (techcrunch.com) 34
NASA has a launch date for that most Hollywood of missions, the Double Asteroid Redirection Test, which is basically a dry run of the movie "Armageddon." From a report: Unlike the film, this will not involve nukes, oil rigs or Aerosmith, but instead is a practical test of our ability to change the trajectory of an asteroid in a significant and predictable way. The DART mission, managed by the Planetary Defense Coordination Office (!), involves sending a pair of satellites out to a relatively nearby pair of asteroids, known as the Didymos binary. It's one large-ish asteroid, approximately 780 meters across -- that's Didymos proper -- and a 160-meter "moonlet" in its orbit.
Don't drop it on China (Score:2)
Accidentally.
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You forgot the air quotes.
Here's hoping (Score:3)
... they don't manage to redirect either one *into* earth.
Re:Here's hoping (Score:4, Funny)
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A better link: https://www.nasa.gov/planetary... [nasa.gov]
"The DART spacecraft will achieve the kinetic impact deflection by deliberately crashing itself into the moonlet at a speed of approximately 6.6 km/s, with the aid of an onboard camera (named DRACO) and sophisticated autonomous navigation software. The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, but this will change the orbital period of the moonlet by several minutes - enough to be observed an
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The asteroid doesn't cross the Earth's orbit, so there's no chance of that happening. It does however come conveniently close in its perihelion which makes this mission possible. The effect of the impact is a velocity change of about half a millimeter per second in the tiny moon that orbits the main asteroid. This will be detectable over time as a change in its orbital period. There's not enough energy in the impact that it could cause the asteroid's orbit to cross Earth's (and the impact won't be from the
I still can't understand (Score:2)
why they always wait until something is really close to Earth before they do something.
You can probably just toss a solar sail on something if it's far away, since a minor change far away is pretty major in terms of deflection.
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Because smaller asteroids are hard to detect far away.
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Errr, you mean like a space telescope.
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I suspect a combination of our atmosphere and light pollution keeps us from spotting such. We had to use Hubble to find a post-Pluto target for the New Horizons probe, which was in a very specific spot in the sky. Our top Earth-based scopes are located on isolated mountains. They can only study a narrow portion of the sky at time and there's not a lot of flat space to build more scopes on such mountains.
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I heard that they've calc'd the orbits of the larger rocks that we can see, and nothing bisects Earth for the next century.
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Indeed, the ones we know about!
The estimated number of asteroids brighter than absolute magnitude of 22.0 (approximately over 140 m across) rose to 27,100±2,200, double the WISE estimate,[95] of which about a third were known as of 2018.
The ones 1km+ in size are a bit vague in numbers but estimates have some 80 or so not yet found.
Fun fact:
The number of asteroi
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why they always wait until something is really close to Earth before they do something.
You can probably just toss a solar sail on something if it's far away, since a minor change far away is pretty major in terms of deflection.
If it is far away and a threat that tends to mean it is going really fast. How are you going to get into position to do anything?
Near is where we can get to in a hurry. If we can't do it near, we can't do it at all.
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In this case, they're choosing an asteroid that's very close to Earth's orbit simply because it makes the mission easier to accomplish, and the results easier to study.
In an actual Earth impact prevention scenario "far" and "close" are more relevant in terms of time than space. A dangerous Earth-crossing asteroid would hopefully be detected and deflected many orbits before the potential impact. The deflecting spacecraft would be built as soon as humanly possible and launched as soon as the orbital mechanics
Density? (Score:2)
Lots of those sorts of things are just loose agglomerations of gravel and dust, rather than one big solid rock.
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Prepare for mirth! They will be looking for evidence of this as it is one of the hypotheses.
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loose pile of gravel and dust much lesser concern when striking Earth though. Lesser a relative term in that we could have global dimming and lose crops for a big enough gravel pile, but at least won't lose city or continent.
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The moonlet they're trying to hit is about 500ft in diameter. That's big enough that it basically doesn't matter whether it's a loose pile of gravel or a solid rock - there's plenty of material to absorb the impact and vaporize the spacecraft in the process. The composition will determine how deep a mark it'll leave, and whether there's any interesting side-effects like plumes of exploding material acting as a short-lived rocket thruster, increasing the amount of deflection.
How about Bruce Willis? (Score:2)
They NEED Bruce Willis on the crew, or you know that the mission is doomed. He doesn't know how to fail!
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And nukes. Nothing real happens unless it has Bruce and nukes: Movie Rule #7
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Waste of taxpayer money (Score:5, Funny)
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You're welcome to listen to them while you read about it.
In fact, are you sure they're not already involved? And why not? Whose fault is it?
Scale (Score:2)
I listened to a segment on "Houston, we have a podcast". They likened it to dropping a golf cart onto a football stadium.
I'm not sure if this is helpful, as they don't specify which football, nor how many hogsheads of beer can be contained within.
Info (Score:4, Informative)
They're estimating that they may slow the orbit of the little moon from 11 hours 56 min to 11 hours 51 min (or thereabouts...I might be misremembering what I heard on a podcast).
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The primary body is about 780 meters in diameter and the moonlet is approximately 160 meters in size. They are separated by just over a kilometer. The primary body rotates once every 2.26 hours while the tidally locked moonlet revolves about the primary once every 11.9 hours. Almost one sixth of the known near-Earth asteroid (NEA) population are binary or multiple-body systems.
The DART spacecraft will achieve the kinetic impact deflection by deliberately crashing itself into the moonlet at a speed of approximately 6.6 km/s, with the aid of an onboard camera (named DRACO) and sophisticated autonomous navigation software. The collision will change the speed of the moonlet in its orbit around the main body by a fraction of one percent, but this will change the orbital period of the moonlet by several minutes - enough to be observed and measured using telescopes on Earth.
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They're also going to test a Xenon thruster in lieu of Willis and nukes.
From https://www.nasa.gov/planetary... [nasa.gov] (now *that's* a cool url to have!)
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If you've seen any Michael Bay movie, you already have seen it. Seriously, there's dialog and actual video that he's duplicated in everything from The Island to Transformers just because he's too lazy to create an entire film from scratch. Armageddon and Transformers 1 + 2 are basically the same freakin' shoot for about half the movies.
Asteroid natives (Score:2)
Or... (Score:1)
Nothing like it (Score:2, Funny)
About the only th
Please realize this is just a test. (Score:2)
There is no need to look into this any further. Things will be just fine.